Systematic Theoretical Investigations on Surface Reconstruction and Adatom Kinetics on AlN Semipolar Surfaces

Abstract

The surface reconstructions and adatom kinetics on AlN(1102) and AlN(1101) surfaces in the presence of H2 molecules are investigated on the basis of density-functional theory calculations. Our surface phase diagram calculations demonstrate that the H-incorporated surfaces are invariably stable over the wide range of H2 pressure. We find that under the growth condition the adsorption energy of Al adatom on AlN(1102) surface is much larger than that on AlN(1101) surface. Furthermore, we find that the diffusion behavior of Al adatom on AlN(1101) surface is significantly influenced by the presence of hydrogen. These results suggest that impact of hydrogen ambient during the metal-organic vapor-phase epitaxy growth on AlN(1102) surface is quite different from that on AlN(1101) surface.

Equilibrium Morphologies of Faceted GaN under the Metalorganic Vapor‐Phase Epitaxy Condition: Wulff Construction Using Absolute Surface Energies

“…Figure shows a performed equilibrium Wulff construction for SAG on the nonpolar lateral direction and calculated absolute surface energies among various orientations depending on Ga chemical potential μ Ga . In this article, these and planes are taken into account as semipolar facets because these planes are mainly observed as facet formation during SAG by MOVPE, and various surface reconstructions on and planes under the MOVPE condition have been proposed by our previous studies . A triangular shape including two and facets is found under the Ga‐rich condition, as shown in Figure a.…”

“…In this article, these ð1122Þ and ð1101Þ planes are taken into account as semipolar facets because these planes are mainly observed as facet formation during SAG by MOVPE, [6,[9][10][11][12][13][14] and various surface reconstructions on ð1122Þ and ð1101Þ planes under the MOVPE condition have been proposed by our previous studies. [35,36] A triangular shape including two f1122g and f1120g facets is found under the Ga-rich condition, as shown in Figure 2a. The area of the f1120g facets gradually decreases and the f1122g facets increases with μ Ga .…”

Recent Progress in Computational Materials Science for Semiconductor Epitaxial Growth

“…The power of this approach is not only on understanding the epitaxial growth processes but also on producing fundamental data such as surface phase diagrams as functions of growth conditions. Surface phase diagrams and elemental growth processes have been extensively investigated using similar approach for various semiconductors except InAs and InP such as GaAs [18,41,[103][104][105][106][107][108] and III-Nirides [7][8][9][109][110][111][112][113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128]. Figure 36 summarizes the calculated surface phase diagrams with different orientations for AlN and GaN under H-rich conditions during MOVPE growth.…”

Theoretical investigations of initial growth processes on semipolar AlN surfaces under metal–organic vapor-phase epitaxy growth condition

“…The methodology used has been explained in detail elsewhere. [10][11][12] In the kinetic MC simulation procedure, 11,[24][25][26] the adsorption probability P ad (x) for Al adatoms impinging on the specific lattice site x is given by assuming the local thermal equilibrium approximation written as…”

“…In our previous studies, surface reconstructions and growth kinetics on various AlN surfaces have been theoretically investigated on the basis of an ab initio-based approach, which takes account of the growth condition such as temperature and pressure. [8][9][10][11][12] In this study, we extend our approach to the initial growth processes on a semipolar AlNð11 "…”